Carburetor main well construction



April 12, 1966 F. J. MARSEE CARBURETOR MAIN WELL CONSTRUCTION Original Filed June 5, 1962 INVENTOR. FEVC/f d' A44/9.555

BY MMX W f 7' 7' OPA/E y 3,245,666 cARBUnEToR MAIN WELL CoNsTRUcTroN vFrederick J. Marsee, Hazel Park, Mich., assignor to Holley Carburetor Company, Warren, Mich., a corporation of Michigan Continuation of application Ser. No. 200,203, June 5, 1962. This application Dec. 14, 1964, Ser. No. 421,143

4 Claims. (Cl. 261-65) induction passage to `provide proper fuel-air r-atios forengine operating conditions above idle.

During normal vehicle operation, and particularly during operationin hot weather, fuel in the main well becomes heated to the point that it tends to percolate and discharge through the main nozzle, particularly after the engine has been shut down. This accumulation of fuel in the induction passage results in an overly rich mixture and causes difficulty during the subsequent starting operation.

Accordingly, it is a general object of the invention to provide means for preventing percolated fuel from entering the induction passage.

A specific object of the invention is to provide a perforated tubular standpipe positioned in the main well just prior to the point ofintersection of lthe main well and the passage through the main nozzle to first dispense percolated fuel before it can spill over the top f the standpipe and second to cause any fuel that does spill over the top of the standpipe .to be returned to the main well before it can be discharged through lthe main nozzle.

`Other more specific objects and advantages of the invention will become apparent when reference is made to the following description and accompanying illustrations wherein:

FIGURE 1 is an elevational view, with portions thereof cut away and in cross-section, illustrating a carburetor embodying the invention, the carburetor being mounted on the intake manifold of an engine.

FIGURE 2 is an enlarged fragmentary view of that .portion of `FIGURE 1 embodying ythe invention;

FIGURE 3 is an enlarged fragmentary end view of the invention taken on the plane of line 3-3 o-f FIGURE 2 and looking in the direction of the arrows.

Referring -to the drawings in greater detail, FIGURE 1 illustrates generally -a carburetor lmounted on an intake manifold 12. The carburetor 10 com-prises an induction pas-sage 14 having the usual choke plate 16, venturi 18, main fuel nozzle 20, and throttle plate 22 therein. A fuel reservoir -24 is generally lformed as an integral part of the carburetor body 10, and associated therewith is a main metering system 26. A conduit 28 containing a main metering jet 30 communicates between the fuel reservoir 24 and the main Well 32 of the main metering system 26.

A main well tube 34 is pressed into the cover portion 3S of the canburetor body 10, as at 36, and is suspended into the main well 32. The main well tube 34 contains one or more bleed passages 38 through its wall so as to communicate with t-he main well chamber 32. A conduit 40 communicates between the open top 42 of the main Well tube 34 and the induction passage 14.

United States Patent.l C)

3,245,666 Patented Apr. 12, 1966 ice T-he main nozzle 20 may be associated with .the main metering system Y26 by virtue of having its tubular inlet end 44 press fitted into the main portion 37 of the carburetor body y10 as at 46, so as to surround the main well 'tube 34. A discharge passage 48 through the stem 50 of the main nozzle 20 communicates between the main well 32 and the induction passage 14. An anti-Siphon bleed 52 communicates between the uppermost end 54 of the discharge passage 48 and the conduit 40 leading to the induction passage 14.

As is better illustrated in FIGURE 2, a cylindrical standpipe 56 is press fitted into the inlet end 44 of the main nozzle 20 such that it surrounds the main well tube 34 and provides a clearance 58 therebetween.

The standpipe 56 comprises a cylinder of any suitable material and of such a length that its lower end is flush with the inlet end 44 of the main nozzle 20 and its uppermost end 62 is substantially below the inlet end 54 of lthe discharge passage 48. The standpipe 56 can be seen, in lFIGURES 2 and 3, to contain yone or more holes 64 through the Walls thereof. These holes 64 are located in that portion of the standpipe 56 which extends above the press lit surface 66 into a countei'bored clearance 68 in the main nozzle inlet end 44. In -those carburetor models which do not cont-ain a main nozzle of the type shown, the standpipe 56 could be press fitted into the wall formingthe main well chamber 32, provided that the upper end of the main well 32 were bored out so as to provide a clearance, similar to the clearance 68, around the upper portion of .the standpipe 56.

The advantage of having a standpipe 56 contained in the main well system 26 is thatany fuel from the lower portion of the main well chamber 32 that is percolated upwardly around the main well tube 34 is permitted to spill out over the top edge of the standpipe 56, into the clearance 68, back through the holes 64, and lthence back down into the main well 32. This prevents the percolated fuel from reaching the inlet end 54 of the main nozzle disch-arge passage 48.

However, in addition to allowing any spilled fuel to return to the main well 32, the holes 64 permit the fuel vapors causing the percolation to escape or be dispersed into the clearance 68, thus serving to substantially de- |crease the intensity of the peroclation and reduce the amount of fuel spillage.

Iu summary, it can be seen that the invention provides novel means for preventing percolated -fuel from being spilled out into the induction passage of the carburetor after an engine has been .shut down, thereby permitting the engine to be properly restarted.

Although but one embodiment of the invention has been shown and described, it is apparent that other modifications of the invention lmay be ymade without exceeding the scope of the appended claims.

What l claim as my invention:

1. In an internal combustion engine carburetion system wherein the heat from the engine tends to at times percolate the fuel in the carburetor, said carburetor having an induction passage, a throttle plate in said induction passage, a main well chamber and a fuel reservoir, a main metering system, said system comprising a main well formed by said main well chamber, a first conduit leading from said fuel reservoir to said main well, a metering jet in said conduit, an air-bleed well tube suspended from the upper portion of said carburetor into said main well, a main fuel nozzle, a passage communicating between said nozzle and said main well, a second conduit communicating between said well tube and said induction passage, and a perforated tubular member, said tubular member being tightly confined around its entire lower outer surface in the main well below the point -of intersection of the said main well and said main `fuel nozzle providing an inner -clearance between said Well tube and said member and van outer vclearance between the upper unconned portion of the outer surface of said` member and said main well for preventing percolating fuel 'from spilling through said -main 1ue11nozzle and into said induction passage, the perforated :portion of 'said vtubular member 'being the only `communication betweensaid outer clearance-andsaid mainwelL 2. In an internal combustion-engine :carburetor wherein the `fuel is subject `to Apercolationdue to Iheat rom lthe engine, ian induction passage, a ,main discharge nozzle in said 'induction `passage, 4a -fuel reservoir, a passageway Vleadingffromsaid reservoirto said `main nozzle, ka stepped main Well formed in said passageway, Aan air-bleed =we1l tubesuspended into =-said main well, :and a cylindrical Vmemberhaving its entire flower outer surface press-fitted into the smallest internal diameter of said stepped main well so as `to `provide a first clearance around said well "tube and a second clearance around the upper portion of -said `tubular member, said tubular member having -at least one perforation formed `through the lwall thereof communicating betweensaid iirst and second clearances.

3. lIn an internal combustion `enginecarbure'tor wherein the'fuel is subject to percolation due to heat from the engine, van 'induction passage, a `main fdischarge nozzle in said induction passage, ya 'fuel reservoir, a passageway leading from-said reservoir 'to said main nozzle, a `main well formed in `rsaid passageway,an air-bleed well tube suspended yinto said main well, a tubular member located in said main well between said well tube and 'the walls of said `main'well *providing afull llength inner clearance betweensaid well tube'an'd said tubular member-and an outer clearance around the upper portion `only of -said .tubular member between said tubular 'member and the `walls of said main well, an internal iiange formedfin said main well, 4said `iiange having an inside v'diameter substantially the same as the outside diameter vof said vtubular Vmember,y and being :located adjacent vthe lower end of said'tubular'member, Va'port formed-infsaid tubular mem-y ber communicating between said clearances, said 4port Vpermitting Avapor to escape tfrom said inner `clearance vto lsaid outer clearance vduring nperiods of kmild percolation and leading from said reservoir to said main nozzle, an yairbleed `wellformed in said passageway, a main well tube suspended into said main well, a tubular member located in said main well between said Well tube and the walls of said main well providing a full length inner clearance between -said well tube yandisaid 4tubular member and an outer clearance around the ,upper portion ronly of said tubular member between said tubular member and the `walls of said main -well,.an internal ring ffornied in Ysaid main =well abutting vagainstthe lower router surfaceof said Vtubular member, aplurality yof fportstormed in -said tubular membercomrnunicating between said clearances, said plurality of ports permitting vapor to .escape -from said inner clearance to said outerclearance duringrperiods of mild ,percolation and serving to permit fuel which has spilledover the -topof said vtubular -mernber into said outer -clearance to return throughsaid yplurality'of portsito said inner clearance and thence `to -said kmain well-.during periyods yo'i violent percolation.

YReferencesl Cited ybythe 4Examiner UNTED ASTATES PATENTS 1,170,416 2/1916 .Claudel 261-41 1,831,056 10/ 1931 'Bicknell 261-41 1,851,343 3/'193'2 Ba'll et a1. 261-41 1,916,062 .6/1933 VMemini 261-4l 2,898,095 `.8/1959 San -Yul An 261-41 X 3,030,085 4/'196'2 Read 26.1-41

FOREIGN PATENTS 604,247 v8/l960 VCanada 465,"474 5/11-93'7 Great LBritain.

HARRY "B. THORNTON, Primary Examiner. 

1. IN AN INTERNAL COMBUSTION ENGINE CARBURETION SYSTEM WHEREIN THE HEAT FROM THE ENGINE TENDS TO AT TIMES PRECOLATE THE FUEL IN THE CARBURETOR, SAID CARBURETOR HAVING AN INDUCTION PASSAGE, A THROTTLE PLATE IN SAID INDUCTION PASSAGE, A MAIN WELL CHAMBER AND A FUEL RESERVOIR, A MAIN METERING SYSTEM, SAID SYSTEM COMPRISING A MAIN WELL FORMED BY SAID MAIN WELL CHAMBER, A FIRST CONDUIT LEADING FROM SAID FUEL RESERVOIR TO SAID MAIN WELL, A METERING JET IN SAID CONDUIT, AN AIR-BLEED WELL TUBE SUSPENDED FROM THE UPPER PORTION OF SAID CARBURETOR INTO SAID MAIN WELL, A MAIN FUEL NOZZLE, A PASSAGE COMMUNICATING BETWEEN SAID NOZZLE AND SAID MAIN WELL, A SECOND CONDUIT COMMUNICATING BETWEEN SAID WELL TUBE AND SAID INDUCTION PASSAGE, AND A PERFORATED TUBULAR MEMBER, SAID TUBULAR MEMBER BEING TIGHTLY CONFINED AROUND ITS ENTIRE LOWER OUTER SURFACE IN THE MAIN WELL BELOW THE 